The present invention relates to a barrier rib forming method for use in fabricating a PDP plasma display panel.
In general, a gas discharge display panel is a displaying element wherein an inert gas is intorduced and sealed between two glass substrates having separated electrodes on each glass substrate, and wherein numerals and letters and the like are displayed by utilizing a gas discharge produced by an applied voltage at the electrodes.
In such devices, a barrier rib is formed to define a pixel and to prevent cross-talk between neighboring cells as well as to maintain a constant gap from anode to cathode.
Japanese laid open patent Sho-58-150248 discloses a prior art gas discharge display panel as discribed above. In this Japanese patent, a conventional screen printing method was utilized in order to form the barrier rib. The conventional barrier rib forming method used in PDP fabrication including usual screen printing may be explained more in detail along with the process sequence shown in FIGS. 2(A)-2(F) as follows:
As shown in FIG. 2(A), after coating an ITO(Indium Tin Oxide), transparent material film 32 for to form a transparent electrode on the surface of the glass substrate 31, as shown in FIG. 2(B), photoresistor 33 is coated on the ITO film 32 by using a spin coater or the like and then dried. Thereafter the photoresistor 33 is exposed to ultraviolet rays by utilizing a mask of predetermined pattern and developed, as shown in FIG. 2(C).
In the next step, the exposed ITO film 32 is etched leaving the photoresistor 33 and the corresponding unexposed portion of the ITO film 32. Next, the photoresistor 33 is removed by a photoresistor stripping solution as shown in FIG. 2(D) and FIG. 2(E) leaving the ITO film 32 to form ITO electrodes 34.
The barrier rib 35 shown in FIG. 2(F) can be formed by a printing and drying process repeated 7 to 10 times with glass paste and a screen mask.
Using this method of forming the barrier ribs 35 by screen printing, a misalignment of the screen mask and the glass substrates can transform and distort the shape of the electrodes and the barrier ribs and particularly change their widths. These transformations, especially the encroachment of glass paste onto the electrode can degrade the discharge characteristics of a PDP. These are troublesome problems to be solved in the art of glass paste printing with a screen mask. For example, the structures of the screen mask should be transformed in accordance with the PDP cell's size.